Prop suggestions

[Ray74]

Right now i have a 15.5x13 3 blade prop on my boat. Wanting to go to a 4 blade . Current prop wot 5800rpms@ 30mph. What size 4 blade should i consider. Motor is a Johnson ocean pro 130 on a 20ft center consol (mako 205dc) pretty deep v hull. It rides kinda bow high. Looking for slower planing speed for when the water gets a lil rougher and for trolling. Thanks

 

[Texasmark]

I just did the same thing with my 115 Merc on a Crestliner 1750 Fish Hawk. I was running a 3 blade SS 20P name brand performance prop and wanted what you want. Went to a 4 blade 19P SS performance prop. Difference was what I wanted and top end dropped about 5-10% as one would expect. Very happy with the change.

 

[Ray74]

Did you keep the same diameter and just drop 1in of pitch?

 

[Faztbullet]

Put a set of tabs on it as your under powered

 

[Ray74]

Boat already has built in tabs

 

[Sea Rider]

Are 5800 wot revs achieved as loaded the max rpm range for that motor ? If having bow up attitude move more load/passengers up front. Prop diam is what the manufacturer wants to play with comparing equal pitch on a 3 or 4 blade prop.

Happy Boating​

 

[Texasmark]

Did you keep the same diameter and just drop 1in of pitch?

The diameter comes in a range to fit the LU. Once in that range...13-14" for 115 range of engines, the diameter varies as a function of the prop design and varies by fractions of an inch. Don't loose any sleep on matching that up or not once in range.

 

[Ray74]

Are 5800 wot revs achieved as loaded the max rpm range for that motor ? If having bow up attitude move more load/passengers up front. Prop diam is what the manufacturer wants to play with comparing equal pitch on a 3 or 4 blade prop.

Happy Boating​

Max rpms for my motor are 5000-6000. Im having trouble findind a 15.5 4 blde prop with 11-13 pitch to keep the rpms in range

 

[Sea Rider]

Max rpms for my motor are 5000-6000. Im having trouble findind a 15.5 4 blde prop with 11-13 pitch to keep the rpms in range

At 5800 wot rpm the motor revs near its max range as loaded which is fine with current 3 blade prop. If the issue is the bow up attitude move some passengers up front, trim motor bit down from previous trim to compensate the ride and check if the problem bettered or was finally solved.

Happy Boating​

 

[Ray74]

Wondering if i go to something like 14.75x15 if it would be close to top of my rpm range. 3 blade 15.5x13 gives me 5800 rpms

 

[Ray74]

Found a 4 blade solas 14.5x13. Would this work good?

 

[Sea Rider]

Found a 4 blade solas 14.5x13. Would this work good?

Only a wot water test as loaded will tell after the new prop has been already purchased, expect assumptions, wild guesings answers to follow...

Happy Boating​

 

[Texasmark]

My mentioned 4 blade is a Solas. Very impressed with the finish, seems to be very high nickel content to reduce corrosion and maintain the shine. Performance as I stated, blade geometry, nice cupping for grip and blade shape to support mid range stern lifting....like I said, made for the intended purpose.....different design than when you prop for top speed and bow lift, not stern lift.........and the nicest part was it was $275, brand new, rubber pressed in hub and free shipping....whadda deal.

Found a 4 blade solas 14.5x13. Would this work good?

 

[Faztbullet]

Are these wedges in the hull or actual tabs that are adjustable ? As stated you about 70 hp under the rating. It riding bow high as cannot lift the stern...so stay with biggest diameter 4 blade

 

[dingbat]

Very impressed with the finish, seems to be very high nickel content to reduce corrosion and maintain the shine.

Nickel has nothing to do with the corrosion resistance or shine of the material.

Nickel is a rather soft, off-white material used to impart “toughness” (make softer, reduces cracking) and reduce work hardening.

Stainless steel’s corrosion resistance comes from its chromium content. The “bling” comes from liberal use of a “rouge” wheel.

 

[racerone]

That would be a V-6 lower unit on that 130 HP.-----Have the boat weighed.------If it has foam flotation it could be waterlogged.

 

[Ray74]

Are these wedges in the hull or actual tabs that are adjustable ? As stated you about 70 hp under the rating. It riding bow high as cannot lift the stern...so stay with biggest diameter 4 blade

Actual adjustable hydraulic tabs

 

[Ray74]

Yes v6 lower unit. Its a heavy boat. Pretty sure some foam is waterlogged. Common problem with these old makos

That would be a V-6 lower unit on that 130 HP.-----Have the boat weighed.------If it has foam flotation it could be waterlogged.

 

[Texasmark]

Nickel has nothing to do with the corrosion resistance or shine of the material.

Nickel is a rather soft, off-white material used to impart “toughness” (make softer, reduces cracking) and reduce work hardening.

Stainless steel’s corrosion resistance comes from its chromium content. The “bling” comes from liberal use of a “rouge” wheel.

Yeah.....brain fart. Sorry. Got my tongue tangled up in my teeth....lost my mind. Grin

 

[Texasmark]

Yeah.....brain fart. Sorry. Got my tongue tangled up in my teeth....lost my mind. Grin

Buttttt: